#include <iostream>
using namespace std;

class Solution {
public:
    static int sum;
    static int i;
    Solution() {
        sum += i;
        i++;
    }
    int Sum_Solution(int n) {
        Solution* arr = new Solution[n];
        return sum;
    }
};

int Solution::sum = 0;
int Solution::i = 0;



int main()
{
    Solution a;
    cout << a.Sum_Solution(5);
    return 0;
}